Pairing HC-05 (or similar) with Mofii Master

[jpanhalt]

I have asked this question of Grok3 and Google and gotten different answers:
"How is an MCU involved in pairing an HC-05 set to slave only mode with a Bluetooth device set as master, such as a Mofii number pad. This question is about PAIRING ONLY, not interpreting any transmitted data. Assume the HC-05 has a low-power LED to indicate when it's paired."

Grok 3:

The HC-05, configured as slave via AT commands, relies on a microcontroller unit (MCU) to manage the pairing process with a Bluetooth master like a Mofii numeric pad. Here's how the MCUin involved in the pairing process: <gobbledegook>

Google:

The MCU's primary role in pairing the HC-05 slave module with a master Bluetooth device like the Mofii number pad is to facilitate the initial pairing process and potentially manage the HC-05's configuration, if needed. The HC-05, in its default slave mode, passively waits for a connection request from a master device. The MCU may not be directly involved in the Bluetooth pairing protocol itself, but it can enable the HC-05's AT command mode to change its configuration, if required. For example, the MCU can send commands to the HC-05 via a serial interface to configure its name, PIN code, or baud rate.

I have looked at several "How to's" for PIC and Arduino (almost anything recent is Arduino) and find nothing specific in the code to send to the HC-05 so long as it is correctly set up as default slave. It appears the RXD pin on the HC-05 can be defaulted high (e.g., with a voltage divider if operating at 5V), which implies it is not needed.

I have successfully paired the two using a laptop and serial port converter with TeraTerm to be sure the HC-05 is properly set with AT commands and confirm data are sent. Now, I am about to try it with a PIC16F1xxx. What I don't know is whether the serial port sent something in pairing mode that I am not aware of. Of course, I could just try it, but I thought to ask here first because AI responses were conflicting and/or confusing.

 

[jpanhalt]

Update: I took a second look at a couple of the non-Arduino threads. The MCU for the slave device being paired (e.g., HC-05) seems simply to be echoing the master device. Update tomorrow.